Controlled Ovarian Stimulation

The aim of controlled ovarian hyperstimulation (COH) for in-vitro fertilization (IVF) is to produce the development of multiple follicles containing eggs in order to harvest a suitable number of eggs which can be fertilised and allow a selection of embryos which can be replaced into the uterus. Interference from a woman’s internal hormones is avoided by suppressing pituitary gonadotrophin production by co-treating with a GnRH agonist or antagonist, each with its own pros and cons. Individually tailoring the programme attempts to achieve the best live birth rates while taking into account the avoidance of ovarian hyperstimulation syndrome and the promotion of patient comfort, performed by utilizing several known facts such as ovarian response in any previous cycles, age, anti-Mullerian hormone (AMH) levels or other predictors of ovarian reserve. The choice of gonadotrophin preparation for COH makes little if any difference regarding live birth rates while the GnRH antagonist is preferred over the agonist as regards patient comfort. Pre-treatment predictions of high, low and normal responders (using age, AMH and/or antral follicle counts) determines the protocol to be used and the starting dose of stimulation.